Remote repositories like GitHub allow you to store you code, data, and other information in a convenient online location. However, most of the time you will want to work on your personal computer and take advantage of a nicer programming interface, or so-called integrated development environment (IDE) like RStudio. Using remotes also allows for easier collaboration among people working in different places. This lesson will introduce you to working with remote repositories and show how to move your files back and forth from the cloud to a local computer. In general, our model for this process looks something like this.
There are several ways to connect a remote repository to your local computer. Here we will see how to do so from within RStudio. RStudio provides a nice interface for using Git for version control via “Projects”. Note that these are different than the GitHub Projects we learned about here.
Task: Navigate to the testing repo we created on GitHub in the lesson on Intro to GitHub.
Task: Highlight and copy the full URL from your browser’s address bar.
Task: Start RStudio
Task: Select File –> New Project…, which will bring up a dialogue box.
Task: Select Version Control
Task: Select Git
Task: In the Repository URL box, paste the full repo address from GitHub that you copied above.
Tip: YOUR_USERNAME in the location
below should be your GitHub user name.
Task: Tab to the next box, Project directory
name, which should auto-fill with the repo name
testing.
Task: Select the directory location where you’d like this project to live.
Tip: I strongly suggest choosing a location that is not under some other version control software such as Dropbox.
Task: Check the box in the lower left that says “Open in new session” and then click on the Create Project button.
Success: RStudio will open a new instance with all of the project files listed.
Tip: Note that the files shown in your project may look different than the image below.
There are several things to note here in RStudio
(note that your views may differ depending on how you have the window
panes set up). In the Files tab, you should see a
README.md file plus the R and
data folders we that we previously created from within
GitHub. In addition, you should see a .gitignore and a
testing.Rproj file.
Click on the .gitignore file to display its contents in
the code pane. You should see 4 file extensions listed there:
.Rproj.user
.Rhistory
.RData
.Ruserdata
This .gitignore file contains information about the
things that you don’t want Git to pay
attention to when tracking different versions of your files and folder
contents. For example, some people want to exclude .html
files that are generated by .Rmd source files, or
environment files unique to R and
RStudio. You can see a list of common options for
R here.
Now locate the Git tab in the pane with other tabs
for Environment, History, etc. and
click on it. You should see both the .gitignore and
testing.Rproj files listed there with an empty box and 2
yellow question marks to the left of each of their names. This is the
Git staging area and Git shows these 2
files as new (i.e., it’s a graphical means for showing the results of
git status).
Go ahead and click the check box in the column marked “Staged” to the
left of the .gitignore file and you will see that a green
A appears in the column marked “Status”. This is
equivalent to typing git add .gitignore via command-line
Git.
Now click on the “Commit” button just above the file name, which will bring up a new commit window.
There are several important things to pay attention to here. The
first is the menu bar across the top, which has buttons for “Changes”
and “History” in the upper left, and “Pull” and “Push” in the upper
right. At the moment, the “Changes” button is active, so you can see the
contents of the .gitignore file displayed below in green.
In this case, the file is brand new to Git, so
everything is highlighted in green. Later you will see how this
changes.
Now go ahead and click on the “History” button just to the left of
the “Changes” button, which will bring up a log of your commit history.
In the example below, the last file committed was
ex_data.csv that we had previously created and committed
directly from GitHub. You can see information about the
the commit author, the date, and the first 7 characters from the unique
commit SHA.
Now click back on the “Changes” tab and type a short but
informative commit message in the box in the upper right. When you
are finished, click the Commit button in the lower
right. This is the equivalent of typing
git commit -m "added gitignore" via command-line
Git.
RStudio now pops open a commit window that displays the commit command and the top and the resulting reply from Git:
[main d20897b] added gitignore
1 file changed, 4 insertions(+)
create mode 100644 .gitignore
Go ahead and click the “Close” button in the upper right, which will
return you to the main commit window. Close that window, which will
return you to the main RStudio viewer. Note that now
the .gitignore file has disappeared from the
Git tab, and only the testing.Rproj file
remains.
Now that we’ve committed our .gitignore file to history,
we can push it up to our remote repo on
GitHub. To do so in RStudio, you click
on the green up arrow.
Now you will see a smaller Git Push window with the following information from Git.
>>> /usr/bin/git push origin HEAD:refs/heads/main
To https://github.com/mdscheuerell/testing
226daed..d20897b HEAD -> main
The first line is the actual Git command for pushing to a remote repo, and the second and third lines are the results of that command.
You’ve now successfully pushed a change on your local computer to your remote repo on GitHub.
Assuming this is your first time working with a remote repo on GitHub, you were very likely to have been asked to enter your password when attempting to push from your local computer up to GitHub. There’s a good
You can now check to see that your committed .gitignore
file was indeed pushed up to GitHub. Switch over to
your browser and navigate back to the testing repo at
https://github.com/YOUR-USER-NAME/testing. You will now see
the .gitignore file listed along with the
README.md file and the other folders. Next to the file
name, you will also see the commit message you used and a time stamp for
how long ago you made the commit and push. (Note: if you don’t see the
file, try refreshing the view on your browser.)
Now let’s see how to pull changes from a remote repo to your
local computer. To do so, we’ll make some changes to our
README.md file on GitHub, commit them, and
then pull them down. Go ahead and click on the pencil icon in the upper
right to edit the README.md file, which will bring up the
editing window.
Make a few changes to the file and then scroll down to the bottom where you can commit those changes.
Type a short but informative commit message and press the green Commit changes button.
Click on either the testing link or eh Code tab to return to the main repo. Here you will see the commit message and time stamp of your newly changed file, as well as its contents.
Now return to RStudio and look in the Git tab for the blue downward arrow. This is how you pull files from your remote repo to your local project.
Go ahead and click on the pull arrow, which will open up a Git Pull window with the following information (note that the alpa-numeric codes on the 3rd and 4th lines will likely differ from your output):
>>> /usr/bin/git pull
From https://github.com/mdscheuerell/testing
d20897b..4222226 main -> origin/main
Updating d20897b..4222226
Fast-forward
README.md | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)
The first line is the actual Git command and the
remaining lines are what Git is reporting back from
git pull, including the file name and its contents.
Go ahead and close this window and then click on the
README.md file in the File viewer, which
will display its contents in an editing window. Notice that it reflects
the recent changes you made to the file from GitHub
Proper version control requires you to keep all of your local and remote repositories synced with one another. Thus, whenever you begin working on a project in RStudio (or elsewhere, for that matter), you should always begin by pulling any changes from your remote repo into your RStudio project.
Similarly, when you are finished editing all of your local files, you should always end by committing those changes and pushing them up to your remote repo.